Accelerated life testing of nano ceramic capacitors and capacitor test boards using non-parametric method

Engineers are searching for a reliable method to determine the time-to-failure (TTF) data of the electronic systems as cheaper as possible. Reliability plays a vital role in electronic devices marketing & sales, product quality, etc. Accelerated Life Test (ALT) and Highly Accelerated Life Testing (HALT) are the latest methodology in the field of life testing of engineering systems. The ALT can be conducted at higher stress level to generate more failure data within short duration of time. The parametric method and non-parametric method are used to convert the accelerated test condition to actual condition. In this paper, the most widely used C0G and X7R nano ceramic capacitor is selected to generate the time-to failure data at accelerated condition and non-parametric method is used to convert the accelerated condition data into actual condition.     

Stress analysis and design for a structural fatigue testing machine

A closed loop servo-hydraulic structural fatigue testing machine was developed. It can apply fatigue loads on actual engineering parts or components for their fatigue strength evaluation. The testing machine consists of a structural bending load frame, a structural torsion load frame, a hydraulic system, and a control system. Stress analysis and design for the crosshead, columns and test bed for the structural bending test frame are described. Finite element analysis was performed for the structural torsion load frame. Evaluation of the structural load frames and application of the test machine are briefly given.     

MEMS材料力学性能的测试方法

介绍国内外MEMS(micro-electro-mechanical system)材料力学性能的测试方法,包括纳米压痕法、薄膜打压法、梁弯曲试验、微拉曼光谱法、单轴拉伸法等.分析各种测试方法的优缺点、基本原理和最新进展.详细介绍单轴拉伸试验方法的试验原理、特点及发展现状, 在此基础上介绍作者们在MEMS材料单轴拉伸试验方面的阶段性研究成果,包括单轴拉伸试样设计、夹具设计、加载方法及应变测量技术等.试样和夹具的设计采用有限元方法模拟不同形状参数试样的拉伸试验过程,确定试样的外形和尺寸.应变测量采用的是激光干涉应变计法(interference strain /displacement gauge, ISDG),并用所研制的微小试样拉伸试验机,成功测得多晶铜薄膜材料的应力-应变曲线.     

Testing and calibration of coordinate measuring arms

Portable coordinate measuring arms with rotational axes have found their place in many industrial areas. To establish and confirm the accuracy of these measuring devices, related test methods and appropriate devices are needed. After an introduction, a new high precision measuring device for testing and calibration of portable coordinate measuring arms is presented. Analysis showed that the best results can be obtained with a device for measuring along a straight line adjusted in various spatial directions. We discuss the design and construction of this measuring system and provide a theoretical calculation of its measurement accuracy, which was confirmed by experiments carried out on a prototype of a high precision measuring device in both unloaded and loaded conditions.     

Study on GNSS satellite signal simulator

Satellite signal simulator for global navigation satellite system（GNSS） can evaluate the accuracy of capturing,tracing and positioning of GNSS receiver.It has significant use-value in the military and civil fields.The system adopts the overall design scheme of digital signal processor （DSP） and field-programmable gate array （FPGA）.It consists of four modules：industrial control computer simulation software,mid-frequency signal generator,digital-to-analog （D/A） module and radio frequency （RF） module.In this paper,we test the dynamic performance of simulator using the dynamic scenes testing method,and the signal generated by the designed simulator is primarily validated.     

基于压缩传感的脉冲超宽带系统窄带干扰估计算法

针对超宽带抗干扰通信中较难实现射频窄带干扰(NBI)估计问题,根据超宽带信号为时域极窄脉冲而窄带干扰为连续波这一主要特点以及窄带干扰的频域稀疏特性,提出了一种基于压缩传感理论的改进正交匹配追踪(OMP)估计算法,该算法以重构误差变化率作为匹配过程的迭代终止条件,在低于奈奎斯特采样率下进行窄带干扰信号频率和幅度估计.理论分析和实验表明,该算法利用射频接收信号的欠采样值,采用较少的迭代次数,可以有效实现超宽带系统中单个或者多个窄带干扰信号估计.     

Issues and mitigation of interference,attenuation and direction of arrival in IEEE 802.15.4/ZigBee to wireless sensors and networks based smart building

The performance metrics of IEEE 802.15.4 standard make it an only dominant option in short-range environmental monitoring and control applications. The heterogeneous sensor and actuator nodes based on the wireless technology are deployed into the smart building environment. Wireless technology deployed in building environment suffers from interference from different communication protocols operating in the same unlicensed ISM band, apart from the attenuation loss. A designer could not ignore these factors in the smart building because the adverse effect of these issues on system performance is considerable. Most of the researchers reported this but not with the aspects of the smart building. This research paper reports on the detailed experimental analysis and mitigation for different types of interference, the direction of arrival and attenuation losses associated with smart building condition. This research also tries to find the mitigation by direction of arrival of the radio signal. Our research aims to generate the customized methodology that will support and assist the smart building system designer to evaluate and measure the on-site performance so that these assessments will be precise, efficient and accurate. A realistic, smart home solution is applied to the building.     

Mine-Detection Test Facilities at TNO-FEL Site “Waalsdorp”: Some Examples of Results Obtained with an Array Based GPR System

At the TNO Physics and Electronics Laboratory (TNO-FEL), one of the recent research programs explores the use of ultra-wide-band (UWB) electro-magnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g., land mines). An experimental UWB ground-penetrating radar system was designed to operate in the frequency band from 200 MHz to 3 GHz and uses impulse radiating antennas (IRAs) as transponders to radiate and receive very short electro-magnetic pulses from a short distance above the soil. Part of the development of this UWB GPR system involved the erection of an outdoor tent covered UWB GPR testing facility. In another program an outdoor multi-sensor humanitarian de-mining test facility was constructed. This facility enables semi-automated measurements, with several different sensor on lanes with different soil types. This article highlights the development of the above mentioned system and facilities and presents some results obtained with one of the commercial systems that is present at the site.     

基于GPRS的高压开关设备远程温度监控系统

针对高压开关设备地域分布广而造成温度信号采集困难和设备难以及时维修的问题,开发了一种基于通用分组无线业务(GPRS)的远程温度测控系统,该系统的数据采集终端以数字信号处理器(DSP)为核心,利用热电堆传感器采集温度,通过GPRS模块连接Internet,利用动态域名解析的办法与监控中心建立连接,再把温度信号传到监控中心进行分析监控,并进行了相关测试。测试结果表明,该系统抗干扰能力强,工作稳定,可对历史数据进行分析,并可对高压开关设备的温度实施有效的远程监控。     

基于虚拟仪器的UWB超宽带射频芯片自动测试系统的研究

本文基于虚拟仪器技术设计了UWB(Ultra WideBand)超宽带微波射频芯片自动测试系统,实现对测试仪器的实时控制,完成UWB射频芯片的各参数测试。并可以通过虚拟测试平台实现测试过程的监测和测试数据的采集、处理,生成测试报告。本系统简化了测试流程,减少了人为引起的干扰,提高了测试效率及精确度,对于UWB超宽带射频芯片的测试和性能评估具有重要意义。     

Joint controller-device design in energy-harvesting networks for the factory of things

A multi-cell multi-input multi-output energy-harvesting network for factory-of-things is considered, where the control panel and smart devices are equipped with multiple antennas. Simultaneous wireless information and power transfer can deliver radio frequency energy for devices in the network, thus formulating the issue of quality of service(QoS). Each cell composes of one control panel and several smart devices where the process of SWIPT causes interference to each other, leading to a complicated non-convex problem. In order to solve it, the linear beamformers and receivers have been designed to maintain the QoS by minimizing the interference. Based on the minimum mean-square-error criterion, an joint controller-device design in which the control panels and smart devices would satisfy the transmit power constraints and the receiving energy bound is proposed. Numerical results of MSE uncover good performance of our proposed algorithm in this network.     

Statistical Analysis of Traction Measurements with Rolling,Sliding, and Spin

Traction measurements, like any other physical testing, contain variability associated with the test rig, test samples, and data acquisition systems. These natural sources of variation increased when simulating contacts with spin velocity in the most common rolling and sliding test conditions. Averaging the results within one test sequence with spinning, rolling, and sliding velocities did not always reflect the expected results from the entire population of possible measured values. To be confident in the conclusions that were drawn from the traction testing, it was important to repeat the test sequence several times and apply statistics for defining error bands around the expected traction values. To allow for easy application of error bands, simplified equations were curve fit to the data from the numerical routines. By making use of error bands, an easy determination of the test repeatability can be discerned, and quantified comparisons between data sets can be made with a higher degree of confidence.     

星载射频组件一体化焊接工艺研究

基于小型化星载射频组件的研制需求,综合利用微组装工艺与表面安装工艺的技术优点,开发了一种一体化焊接工艺,通过陶瓷封装高铅植球、印制电路板/腔体焊接和低空洞真空汽相焊接,完成了对系统级封装（System in Package, SiP）器件、多层射频板、射频绝缘子、金属腔体和双面安装器件的一体化高可靠焊接。产品性能测试、环境试验及工艺鉴定试验表明,该工艺在生产周期、装配效率、一次合格率、性能一致性、长期可靠性等方面具有突出的优势。     

超宽带脉冲信号的波形设计研究

UWB无线通信脉冲发射波形的优化设计不仅能够大大提高UWB系统的位误码率（BER）性能,而且还可以优化UWB无线系统的设计、提高功率效率、降低干扰并使得UWB无线通信系统与其它传统的通信系统能够更好地共存。脉冲波形设计在UWB系统中具有重要作用与意义。文章根据超宽带系统的特点与需求,提出了成形脉冲设计的具体要求和相关的评价指标。并介绍了UWB成形脉冲中几种典型超宽带成形脉冲。主要介绍了：高斯脉冲及其各阶导数脉冲、Hermite正交脉冲以及扁长椭球波函数（PSWF）正交脉冲等的实现原理和特点,最后介绍了脉冲波形设计过程中需要注意的一些影响因素。     

Issues of ultrasonic testing of extended complexly structured items with strong attenuation of signals

These and subsequent articles present the results of the studies of interference resistant methods and devices for ultrasonic testing of extended items made of complexly structured materials. The presented results are based on the radio-engineering R &; D that have been conducted for over 30 years by the Department of Electronic Devices of the Moscow Power Engineering Institute. The studies are concurrently focused on the development of methods for separating echo signals from white and structural noise, on the application of complexly modulated signals, on the development of spatial and temporal methods for processing signals, on the development of broadband mosaic transducers, and on the design of multifunctional devices for ultrasonic testing. The necessity of such a comprehensive approach to ultrasonic testing is substantiated in this article by analysis of the problems of ultrasonic testing of complexly structured items with strong integral attenuation of ultrasound.     

Nanoscale surface deformation inspection using FFT and phase-shifting combined interferometry

In this paper, a flexible optical interferometer incorporated with both fast Fourier transform (FFT) and phase-shifting method is developed for three-dimensional (3D) testing of micro-components. Using light interference, microscopic optics, piezoelectric transducer (PZT) nanoscanning and a CCD camera, the proposed system can detect deformation and surface contour in the order of nanometers. An application of the proposed technique is demonstrated using two micro-components: a micro-beam in an accelerometer and a micromirror. The resulting interference fringes that are related to the deformation and surface contour are analyzed using FFT method or three-step phase-shifting method depending on the test surface features. Experimental results show the feasibility of the proposed method for 3D deformation and surface contour measurement of micro-components.     

轴向柱塞变量泵综合性能测试CAT试验台设计

为准确评估轴向柱塞变量泵的性能,同时提高产品性能检测的效率和准确度,设计了基于CAT(Com-puter Aided Testing,计算机辅助测试)技术的泵综合性能测试试验台。对试验台液压系统进行了原理设计和优化;进行了CAT系统的软、硬件设计;通过分析泵的效率试验验证该性能测试试验台的设计是合理的。     

复杂坏境下基于SINS/UWB的容错组合定位技术研究

针对超宽带无线定位系统在复杂坏境中出现的定位数据丢失以及粗大误差等导致SINS/UWB组合系统定位精度下降的问题,提出了一种基于超宽带定位系统容错判断的组合定位方法。首先根据捷联惯导测量值进行基于中值滤波的运动载体静止状态检测,进而利用最小二乘法实现静止状态下捷联惯导量测偏差矫正;然后在建立SINS/UWB组合定位模型的基础上,引入决策树容错判断机制,对超宽带定位系统在复杂环境中由于信号干扰以及非视距导致的测量数据丢失以及粗大定位误差进行实时评估,进而应用卡尔曼滤波算法,实现容错组合定位系统的构建。在搭建的SINS/UWB组合定位实验平台中进行模型验证,结果表明容错组合定位系统能够有效检测出UWB定位系统出现的定位数据丢失以及粗大定位误差,并且在UWB粗大误差状态持续6 s的情况下,容错组合定位系统仍然能够保持较高的定位精度。     

The MFL Testing Methods for Welded Pipes

Steel pipes are categorized into seamless pipes and welded pipes,and particularly the welded pipes’ NDT(Non-Destructive Testing)has been a challenging problem.In the case,on the basis of the presentation of welded pipes,the analysis of its relevant testing key is carried out.Afterwards,the MFL(Magnetic Flux Leakage)methods for longitudinally welded line-pipes and for helically welded pipes are respectively proposed.Meanwhile,their relevant experiments are conducted,and finally the two technologies for the two types of welded pipes are verified well.